PCF3 // Web-based assessment has been a major research area in recent years, but none of the efforts have yet been directed towards providing adaptive features (either adaptivity or adaptability) for the learner. ʹAdaptivityʹ requires the system to automatically adapt to the learnersʹ current level of domain competence and other similar attributes, whereas ʹadaptabilityʹ requires the system to provide suitable interfaces by which the user can customise the system according to his/her own preferences. This research explores the potential of adaptivity in the Web-based assessment environments and develops a framework that adapts selection of questions within pre-defined contextual boundaries and tolerances and revises granularity in the presentation of questions at varying degree of complexity. // Based on the framework, an adaptive Web-based quiz system is designed and implemented for a first year course at the Massey University. The system is divided into two areas: exercise area and self assessment area. The system uses a student model to monitor and record each student’s exercise and assessment profile. Based on the individual profile, the system presents to the student the suitable exercises at appropriate level of complexity. For example, if the student selects to take an assessment, the system provides the suitable level of questions to the student, based on his or her profile. When the student submits the answers, the system analyses the results according to the marking rules defined by the quiz designer, and gives proper feedback to the student. The feedback includes the correct answers and next recommended step, e.g. system recommends the student to go to the next level if the student gets the satisfying results. Otherwise, the system recommends the user to either try the exercises again or go to revise the relevant learning material. With this system, students are able to take the individualized assessment, and know their own level of competence and the learning progress. Currently, the system is being used by about 150 students. An evaluation is underway to ascertain the effectiveness of the system. Anecdotal comments from the students at this early stage suggest that the students are finding the system as very useful and helpful.